Can my HOA come onto my property to mow my lawn without my permission? There is no bi-law in the HOA docs stating that they can.

You have to make sure you are reading the Declarations AND the Bylaws to see what authority they have to correct covenant violations. Sometimes the language is not in the same section as the list of restrictions for maintenance and use of the property. Sometimes it's towards the end. Even if they do have the authority, they must first provide you with notice and a chance to correct the problem. Central Florida has had a significant amount of rainfall the past few weeks, so uncut grass is a pretty common situation right now. You may want to hire a lawyer to check over your documents just to be sure. If there is no language in the documents, file a report with the police. They will not do anything, but it establishes a record. If the HOA has a property manager responsible for this you can file a complaint against their license. The HOA itself is not regulated by any state agency. You will most likely get a bill for the mowing. At that point you have to decide if it's cheaper to pay the bill or a lawyer to fight the bill.

They normally have this power. There would not a particular provision in the CC&Rs/By Laws saying "we can come and mow your lawn". It's usually a broad power clause that they can enter the property to enforce maintenance, aesthetics, and the rules. Read the CC&Rs/By Laws and if you do not see such a clause, then go to the next HOA meeting and ask them what authority they are relying upon, and get the minutes of the meeting as proof of what was said. If not satisfied, then take the minutes, CC&Rs/By Laws, and any correspondence you have on this issue to a local HOA attorney for review. I have never seen a set of CC&Rs/By Laws that does not have such a provision.